1. Field of the Invention
The present invention relate to a breaking apparatus for glass substrates and, more particularly, to a breaking apparatus for glass substrate, which has an air buffering structure to prevent crack spreading and complete breakage of an abnormally scribed glass substrate in removal of a trim from the glass substrate.
2. Description of the Related Art
In manufacture of flat panel displays such as LCDs, PDPs, and the like, glass substrates are generally used. Glass substrates for flat panel displays are prepared in a large size sheet, which is cut to a suitable size for the flat panel displays.
There are various glass substrate cutting methods such as a wheel scribing method, a laser cutting method, and the like. The wheel scribing method employs a cutter wheel, and the laser cutting method employs laser beams. In these methods, a cutting line, for example a scribing line, is preliminarily formed on a surface of a glass substrate, and load is applied to the cutting line using a breaking bar to cut the glass substrate.
The conventional breaking apparatus has a compressing bar structure which includes a breaking bar vertically reciprocated by a drive unit such as an actuator.
When cutting a glass substrate using the conventional breaking apparatus, a breaking bar is disposed above the glass substrate to be positioned parallel to a scribing line previously formed on the glass substrate and is lowered to press the glass substrate along the scribing line such that a crack formed on the glass substrate along the scribing line is deepened, thereby cutting the glass substrate.
However, when cutting the glass substrate by any conventional method such as the wheel scribing method or the laser cutting method, scribing failure occurs in different ways depending on the kind of cutting method employed. For example, in the wheel scribing method, the glass substrate can undergo scribing failure due to abrasion of the scribing wheel or abnormal setup after replacement which results in non-generation of a lateral crack on the surface of the glass substrate and a median crack on a facet of the glass substrate.
The conventional breaking apparatus is operated simply by pressing the breaking bar. Thus, the breaking bar forcibly presses a trim of the substrate by applying the same stroke, irrespective of whether the glass substrate is successfully scribed or not, so that the glass substrate can be completely broken due to spreading of a lateral crack at a position of scribing failure.
As such, when the glass substrate is completely broken during the cutting process, it takes lots of time to remove the broken glass particles, thereby reducing productivity. Moreover, the broken fine glass particles cause contamination and scratches on the surface of the glass substrate for display panels which require a high degree of cleanliness, thereby causing reduction in yield and productivity.